Apollo, Michal (2017-01-02). "The good, the bad and the ugly – three approaches to management of human waste in a high-mountain environment". International Journal of Environmental Studies. 74 (1): 129–158. doi:10.1080/00207233.2016.1227225. ISSN0020-7233. S2CID113843846.
Apollo, Michal (2017-01-02). "The good, the bad and the ugly – three approaches to management of human waste in a high-mountain environment". International Journal of Environmental Studies. 74 (1): 129–158. doi:10.1080/00207233.2016.1227225. ISSN0020-7233. S2CID113843846.
Apollo, Michal (2017-01-02). "The good, the bad and the ugly – three approaches to management of human waste in a high-mountain environment". International Journal of Environmental Studies. 74 (1): 129–158. doi:10.1080/00207233.2016.1227225. ISSN0020-7233. S2CID113843846.